<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>DOM对象转化成jQuery对象</title>
	<script src="http://apps.bdimg.com/libs/jquery/2.1.4/jquery.min.js"></script>
</head>
<body>
	<div>元素一</div>
	<div>元素二</div>
	<div>元素三</div>
	<script>
		var div = document.getElementsByTagName("div");
		var $div = $(div);
		var $first = $div.first();
		$first.css('color','red');
	</script>
</body>
</html>